(Rolling Stone) -- You have to admit, it's been a minute since Lil Wayne had a chance to sound crazy.

That wasn't a problem back in his madcap creative outburst of 2006 and 2007. For sheer intensity, you could only compare Wayne to the young Bob Dylan, firing out brilliant tunes faster than anyone could absorb them, with his flurry of "Drought and Dedication" mixtapes.

But like Dylan, he had to crash sometime. Since "Tha Carter III," it's been down to a jail term, occasional mixtapes and the rap-rock flop "Rebirth," where he proved there are limits to what even a genius can do with Limp Bizkit as a role model.

So it's thrilling how unhinged Weezy sounds on "Tha Carter III's" proper followup, as he freestyles about shooting for the stars and making astronauts dodge bullets. He comes out of the gate strong with the bleak manifesto of "Intro," declaring, "Life's a crazy bitch, Grace Jones/Mind of a genius with a heart of stone."

Weezy doesn't have the same speed-demon intensity he had five years ago -- and he's just as casual and sloppy about his approach to official album releases. So "Tha Carter IV" has experiments that fail, as well as a pair of star-studded guest tracks where Wayne doesn't appear at all. (Though Andre 3000 is great in "Interlude.") Yet even the failed moments sound like nobody else -- check out "It's Good," with its threat to kidnap Beyoncé so Jay-Z can pay the ransom money. That's impressively tasteless, if nothing else. And the music is sampled from the Alan Parsons Project's 1976 prog-rock opus "Tales of Mystery and Imagination," which is just plain insane.

The best parts of "Tha Carter IV" range from "President Carter," an anti-war rant over a spooky harp loop, to the spaced-out Rick Ross duet "John," where Wayne says, "If I die today, remember me like John Lennon." (Ross already used that line last year on Teflon Don, but Weezy's been comparing himself to Lennon since his amazing 2006 mixtape version of the Beatles' "Help!")

Another highlight is the deservedly huge single "She Will," with Drake singing the bittersweet booty-club hook as Weezy ponders the simple pleasures in life: "Now I like my house big and my grass soft."

There's also his yacht-rock oddity "How to Love," where the acoustic guitar, finger snaps and synth strings build up into some strange mélange of early Air Supply and Al Green. He pushes the same formula in a couple of sequels here, including the miserably soggy T-Pain duet "How to Hate." But he has more luck with the John Legend collabo "So Special," an R&B goof where Weezy claims, "We don' t even f--- no more, we make love."

Lil Wayne spends most of "Tha Carter IV" brooding over death, imprisonment and the passing of time -- there might be more clocks than weapons mentioned, and as he says in "Blunt Blowin'," he's got "gunpowder in my hourglass."

Wayne knows it's not 2007 anymore. But the high points here prove he's already looking ahead to the future.